Tough machines

All share one critical challenge: making tough machines without breaking the bank.

The challenge comes from the fact it is probably possible to construct computers capable of surviving almost anything, if you are willing to spend enough time and money. In the real world, the needs of the military and industry demand that extreme solutions use cheap and readily available components whenever possible to deliver fast deployments at a reasonable price, using accepted standards so that technicians and programmers are easy to find and don’t cost a fortune to hire.

‘You start with a requirement,’ Brennan explains. ‘Then you look at the problem sensibly. There’s a tradeoff between something that meets a full military specification and could survive a thermonuclear blast, and achieving value for money. We try to sit in between.’

This gentle compromise means that most extreme computing teams work with what they call Commercial Off The Shelf (COTS) equipment.

COTS kit is nearly always based on technology originally designed for the mass market in desktop computers – CPUs, drives, video cards, all the stuff we’re used to -- then toughened in various ways by specialist manufacturers. Because it uses common components that have passed all manner of safety tests before they reach the public, the military and other users sign off on COTS equipment pretty fast.

Another grade of equipment – Military Off The Shelf (MOTS) – is trickier. MOTS gear can be rated to survive hazards like the electromagnetic pulse that follows nuclear explosions -- the type of circumstances most of us would really rather not think about, but which the military has to -- and is therefore required to pass many more tests.

The time these tests require means the equipment is sometimes a generation or two old by the time it is finally approved, a massive hassle because using old technology means performance is poor and stocking spares becomes a nightmare.
Every extreme computing project therefore weighs up all these factors before settling on a combination of parts to do the job, a task that makes the job of the technical elite just a little less fun because they aren’t often playing with the latest and greatest technology.

Building blocks

COTS equipment may not be bleeding edge, but the basic building block of most extreme computers, the Single Board Computer (SBC), is still a very interesting creature.

SBCs pack an entire computer into tiny packages that can make even Via’s six layer 12cm x 12cm Nano-ITX motherboards look unwieldy.

Several single board standards co-exist in the marketplace. Little Board packs an entire computer onto one card. ISA modules’ large size will be familiar to anyone that played with PCs in the mid-80s.

The PC 104 standard takes the idea even further by using 90mm x 96mm boards to host individual components. You can buy a CPU board, a graphics board, a WiFi board and many other exotic boards and stack them into a working computer without the need for a backplane or motherboard. So if a tank battle fries your CPU or you want to upgrade your tank to tank LAN to 802.11g, just snap in a new board.

Single board computers can be very impressive: E-value Technology’s EES 3410’s packs a Geode CPU, built-in audio and video, Ethernet, USB serial and parallel ports, a 144-pin SODIMM socket and even a single 2.5’ drive bay into its 106mmx178mmx65mm chassis, yet sells for under $1000. Pentium-powered machines can be found for similarly low prices.

Most use surprisingly familiar, simple and affordable variants on the components that make up an everyday desktop PC. Cost is again the culprit: designing custom components or operating systems to survive harsh environments would be prohibitively expensive.

But not any old equipment will do the job. Equipment intended for office use can survive in extreme environments but won’t survive for long and may not perform predictably. The last thing users in extreme environments want is to make a service call that could take days to answer. Replacing components or rebuilding systems regularly is also a no-no: there aren’t many system integrators in combat zones or down a mine shaft and even the best support will be too slow if you rely on a computer to survive.

SBCs answer the call. Most are hardened to operate at up to sixty degrees and are built to be resistant to vibration, dust and moisture (perfect for LANs, really!).

Their designers achieve these temperatures by thinking about heat from the moment they start to work on a new product. While the designer of a motherboard destined for use in a desktop PC would consider where it would be possible to place a fan or heat sink given the size of the average case, SBC designers consider the airflow between every component, locate the hottest components as far away from each other as possible and add heat-removal features to the board wherever and whenever possible.

They might also consider how to use products like US company Thales Computers’ ‘Ruggedizer,’ an aluminum heat sink designed to sit beneath a board to draw away heat and ridged to enhance insulation between the hottest components. Thales promises its device enables a single board machine to operate at up to 85 degrees!

SBCs and the components they house are also likely to receive a ‘Conformal Coating,’ special silicon-based preparations that are sprayed on all components in a layer a few hundredths of a millimeter thick. Conformal coatings protect the components from dust and moisture, reduce the risk of short circuits, help counter vibration and even act to prevent the migration of metals from one component to another that happens in the electromagnetically charged environment that is the innards of a computer.

Other PC components have their own tricks to bring them into the world of extreme computing. Some off the shelf hard drives, such as those from Seagate, already use Fluid Dynamic Bearings motors, which see the ball bearings suspended in special liquid. The liquid ensures that the bearings never actually touch other components, so that knock and bumps aren’t transferred through the spindle into the platters. Fluid also reduces overall vibration. Other drives, including some pioneered by IBM, use a defense mechanism that detects when a drive is in free fall and removes the read/write heads from the disk platter before impact so they do not gouge holes in the magnetic media. Gel-filled pads round out the protection package by giving drives a soft spot to sit and land on within laptop computers.

This kind of ruggedisation only gets you so far, however. To build a machine that thrives in extreme environments, there’s much more work to be done.